Variously known as promo girls or booth babes -- and rarely addressed by name (or indeed using words) -- these hard-working, high-heel wearing women saunter around your average event in an effort to entice punters to visit their exhibits.

The hours are long, the outfits are skimpy, and the leering "Do you come with the car?" comments come thick and fast. So what's the appeal in being a promo girl?